1. Field of the Invention
The present invention relates to vacuum-operated solder-removing tools.
2. Description of Related Art
Various vacuum-operated solder-removing tools have been previously disclosed. U.S. Pat. No. 4,274,176 to Undin et al. describes such a device including a tubular body with a nozzle at one end thereof, a releasable locking device at the other end, and a piston device therein. The piston device has a piston member mounted on a rod employing a pair of springs.
The main disadvantage of Undin et al. is that it does not provide a shock-absorbing or damping means to absorb, damp, or retard the shock caused by the recoil of the piston device. When the piston device recoils and strikes the releasable locking device, the shock may dislodge some solder that has been drawn into the tubular body, the solder falling back onto the circuit or working space. The shock also makes it difficult to accurately place the solder-removing tool in highly-toleranced circuits, with the shock even jolting the tool into the circuit or a pad thereof. The shock can also decrease the life of the tool.
Another disadvantage of the above invention is that it does not provide adequate sealing between the piston member and the tubular body. Undin et al. provide a resilient sealing disc sandwiched between two retainer discs. By the configuration of the piston member, the resilient sealing disc is subject to accelerated wear due to the differences in the diameters of the discs. Also, it is not guaranteed that the seal between the resilient sealing disc and the piston rod is airtight.
A further disadvantage of the above invention is the provision of two springs. One of the springs, a compression spring, abuts the piston member. This configuration permits the piston member to cock slightly during recoil, thereby possibly reducing the vacuum produced during recoil.
The present invention is directed in eliminating the disadvantages found in the above related art, as well as other related art solder-removing tools.